/**
 * Created by Chenxj on 2016/1/12.
 */

let csm=[];
(function () {
    var cs="0123456789abcdef";
    var n=0;
    for(var i=0;i<16;i++){
        for(var j=0;j<16;j++,n++){
            csm[n]=cs[i]+cs[j];
        }
    }
})();
function rotl(a, b) {
    return a << b | a >>> 32 - b
}
function endian(a) {
    if (a.constructor == Number){
        return rotl(a, 8) &
            16711935 |
            rotl(a, 24) &
            4278255360
    }
    for (var b = 0; b < a.length; b++){
        a[b] = endian(a[b])
    }
    return a
}
function bytesToHex(a) {
    var s='';
    for(var i=0;i<a.length;i++){
        s+=csm[a[i]&0xff];
    }
    return s;
}
function bytesToWords(a) {
    for (var b = [], c = 0, d = 0; c < a.length; c++, d += 8) {
        b[d >>> 5] |= a[c] << 24 - d % 32;
    }
    return b
}
function wordsToBytes(a) {
    for (var b = [], c = 0; c < a.length * 32; c += 8) {
        b.push(a[c >>> 5] >>> 24 - c % 32 & 255);
    }
    return b
}
function FF(a, b, c, d, x, s, t) {
    var n = a + (b & c | ~b & d) + (x >>> 0) + t;
    return ((n << s) | (n >>> (32 - s))) + b;
}
function GG(a, b, c, d, x, s, t) {
    var n = a + (b & d | c & ~d) + (x >>> 0) + t;
    return ((n << s) | (n >>> (32 - s))) + b;
}
function HH(a, b, c, d, x, s, t) {
    var n = a + (b ^ c ^ d) + (x >>> 0) + t;
    return ((n << s) | (n >>> (32 - s))) + b;
}
function II(a, b, c, d, x, s, t) {
    var n = a + (c ^ (b | ~d)) + (x >>> 0) + t;
    return ((n << s) | (n >>> (32 - s))) + b;
}
function md5(m, hash) {
    var a = hash[0], b = hash[1], c = hash[2], d = hash[3];
    for (var i = 0; i < m.length; i += 16) {
        var aa = a, bb = b, cc = c, dd = d;
        a = FF(a, b, c, d, m[i + 0], 7, -680876936);
        d = FF(d, a, b, c, m[i + 1], 12, -389564586);
        c = FF(c, d, a, b, m[i + 2], 17, 606105819);
        b = FF(b, c, d, a, m[i + 3], 22, -1044525330);
        a = FF(a, b, c, d, m[i + 4], 7, -176418897);
        d = FF(d, a, b, c, m[i + 5], 12, 1200080426);
        c = FF(c, d, a, b, m[i + 6], 17, -1473231341);
        b = FF(b, c, d, a, m[i + 7], 22, -45705983);
        a = FF(a, b, c, d, m[i + 8], 7, 1770035416);
        d = FF(d, a, b, c, m[i + 9], 12, -1958414417);
        c = FF(c, d, a, b, m[i + 10], 17, -42063);
        b = FF(b, c, d, a, m[i + 11], 22, -1990404162);
        a = FF(a, b, c, d, m[i + 12], 7, 1804603682);
        d = FF(d, a, b, c, m[i + 13], 12, -40341101);
        c = FF(c, d, a, b, m[i + 14], 17, -1502002290);
        b = FF(b, c, d, a, m[i + 15], 22, 1236535329);
        a = GG(a, b, c, d, m[i + 1], 5, -165796510);
        d = GG(d, a, b, c, m[i + 6], 9, -1069501632);
        c = GG(c, d, a, b, m[i + 11], 14, 643717713);
        b = GG(b, c, d, a, m[i + 0], 20, -373897302);
        a = GG(a, b, c, d, m[i + 5], 5, -701558691);
        d = GG(d, a, b, c, m[i + 10], 9, 38016083);
        c = GG(c, d, a, b, m[i + 15], 14, -660478335);
        b = GG(b, c, d, a, m[i + 4], 20, -405537848);
        a = GG(a, b, c, d, m[i + 9], 5, 568446438);
        d = GG(d, a, b, c, m[i + 14], 9, -1019803690);
        c = GG(c, d, a, b, m[i + 3], 14, -187363961);
        b = GG(b, c, d, a, m[i + 8], 20, 1163531501);
        a = GG(a, b, c, d, m[i + 13], 5, -1444681467);
        d = GG(d, a, b, c, m[i + 2], 9, -51403784);
        c = GG(c, d, a, b, m[i + 7], 14, 1735328473);
        b = GG(b, c, d, a, m[i + 12], 20, -1926607734);
        a = HH(a, b, c, d, m[i + 5], 4, -378558);
        d = HH(d, a, b, c, m[i + 8], 11, -2022574463);
        c = HH(c, d, a, b, m[i + 11], 16, 1839030562);
        b = HH(b, c, d, a, m[i + 14], 23, -35309556);
        a = HH(a, b, c, d, m[i + 1], 4, -1530992060);
        d = HH(d, a, b, c, m[i + 4], 11, 1272893353);
        c = HH(c, d, a, b, m[i + 7], 16, -155497632);
        b = HH(b, c, d, a, m[i + 10], 23, -1094730640);
        a = HH(a, b, c, d, m[i + 13], 4, 681279174);
        d = HH(d, a, b, c, m[i + 0], 11, -358537222);
        c = HH(c, d, a, b, m[i + 3], 16, -722521979);
        b = HH(b, c, d, a, m[i + 6], 23, 76029189);
        a = HH(a, b, c, d, m[i + 9], 4, -640364487);
        d = HH(d, a, b, c, m[i + 12], 11, -421815835);
        c = HH(c, d, a, b, m[i + 15], 16, 530742520);
        b = HH(b, c, d, a, m[i + 2], 23, -995338651);
        a = II(a, b, c, d, m[i + 0], 6, -198630844);
        d = II(d, a, b, c, m[i + 7], 10, 1126891415);
        c = II(c, d, a, b, m[i + 14], 15, -1416354905);
        b = II(b, c, d, a, m[i + 5], 21, -57434055);
        a = II(a, b, c, d, m[i + 12], 6, 1700485571);
        d = II(d, a, b, c, m[i + 3], 10, -1894986606);
        c = II(c, d, a, b, m[i + 10], 15, -1051523);
        b = II(b, c, d, a, m[i + 1], 21, -2054922799);
        a = II(a, b, c, d, m[i + 8], 6, 1873313359);
        d = II(d, a, b, c, m[i + 15], 10, -30611744);
        c = II(c, d, a, b, m[i + 6], 15, -1560198380);
        b = II(b, c, d, a, m[i + 13], 21, 1309151649);
        a = II(a, b, c, d, m[i + 4], 6, -145523070);
        d = II(d, a, b, c, m[i + 11], 10, -1120210379);
        c = II(c, d, a, b, m[i + 2], 15, 718787259);
        b = II(b, c, d, a, m[i + 9], 21, -343485551);
        a = (a + aa) >>> 0;
        b = (b + bb) >>> 0;
        c = (c + cc) >>> 0;
        d = (d + dd) >>> 0;
    }
    return [a, b, c, d];
}
self.hash = [1732584193, -271733879, -1732584194, 271733878];
self.hasFirstHash=false;
self.addEventListener('message', function (event) {
    var block   = event.data.block;
    var output  = {'block' : block};
    if(!block.stop){
        var nBitsTotal, nBitsLeft, nBitsTotalH, nBitsTotalL;
        var message = endian(bytesToWords(new Uint8Array(event.data.msg)));
        event = null;
        if (block.end === block.fileSize) {
            //MD5
            nBitsTotal =  block.fileSize << 3;
            nBitsLeft = (block.end - block.start) << 3;
            nBitsTotalH = Math.floor(nBitsTotal / 0x100000000);
            nBitsTotalL = nBitsTotal & 0xFFFFFFFF;
            message[nBitsLeft >>> 5] |= 0x80 << (nBitsLeft % 32);
            message[(((nBitsLeft + 64) >>> 9) << 4) + 15] = nBitsTotalH;
            message[(((nBitsLeft + 64) >>> 9) << 4) + 14] = nBitsTotalL;
            self.hash = md5(message, self.hash);
            output.result = bytesToHex(wordsToBytes(endian(self.hash)));
        } else {
            if(!self.hasFirstHash&&block.step==3){
                //为不影响后面的计算，这里进行数组浅拷贝，（对于多维数组需要深拷贝）
                var copyHash=self.hash.concat();
                output.firstHash=bytesToHex(wordsToBytes(endian(copyHash)));
                self.hasFirstHash=true;
            }
            self.hash = md5(message, self.hash);
        }
        message = null;
        self.postMessage(output);
    }
}, false);
